The authors analyzed ultrasonographic findings of 112 cases of trophoblastic diseases which were confirmed by D&E or hysterectomy at Wallace Memorial Baptist Hopital from September 1980 to December 1984. The results were as follows; 1. Of all 112 cases, hydatidiform moles were 99 cases, invasive moles were 3 cases and choriocarcinomas were 10 cases. 2. 81 cases(72%) occurred in 3rd decades. 3. The size of uterus was large for gestational weeks in 65 cases(56%) and smaller in 13 cases(13%). 4. The contour of uterus was globular in 59 cases(53%), diffuse in 49 cases(44%) and nodular in 4 cases(3%). 5. The internal echopatterns of uterus revealed numerous small vesicular snowstorm patterns in all cases, and revealed internal degeneration in 67 caes(60%). 6. Uterine walls in 89 cases(79%) were well delineated but uterine walls in 23 caes(21%) were poor delineated. 7. Multiseptated ovarian theca lutein cysts were seen in 36 cases(32%). 8. Invasive trophoblastic diseases(invasive mo es 3 cases and choriocarcinomas 10 cases) revealed similiar ultrasonographic findings with H-mole, but more irregular internal echoes and irregular echoes in uterine wall. 9. Diagnostic accuracy was diagnostic in 98 cases(88%), nonspecific in 11 cases(10%) and error in 3 cases(2%).